At present it is reported that 90% of 40 year olds in the Thai population suffer from gingivitis, of which 80% can go on to develop to periodontitis when they are 60 years old. Patients have an inflammation of gingiva, alveolar bone, cementum and periodontal ligament, characterized by apical migration of the junctional epithelium, and loss of connective tissue attachment between the gingival fibre, periodontal ligament and cementum. There is resorption of the alveolar bone and development of pocket formation. If left untreated, the disease progresses to destruction of the supporting bone, whereby tooth mobility may be observed and sometimes periodontal abscess is found.
The basic treatment, from a patient's perspective, is oral hygiene instruction to control dental plaque and, from the dentist's perspective, is scaling and root planing. This procedure is not always sufficiently effective. This has led to the adjunctive use of antibiotics, usually in the form of a local delivery system rather than as a systemic antibiotic. Systemic antibiotics can cause side effects, for instance systemic metronidazole can irritate the gastrointestinal tract, and, in repeated doses, can affect the nervous system, skin and kidney. Alcohol consumption is not permitted during the period of taking this drug. In the case of systemic tetracycline, this must be used long-term, and in a high dose in order to maintain an effective concentration in the periodontal pocket. Consequently, the normal microorganism environment may be disturbed and super infected by fungus, and development of bacterial resistance strains may occur.
An early development of a local delivery system used a non-biodegradable carrier substance that had to be removed after the release of the antibiotic agent. This system had many disadvantages, as follows: initially, it was difficult to insert the drug into the periodontal pocket, and after complete release of the antibiotic agent, the patient had to return to see the dentist for removal of the carrier. The need to remove the carrier might be harmful to gingival healing and also irritating to the gum.
Recently, controlled local delivery systems using biodegradable substances have been developed to solve this problem. These contain antibiotic and, although they are beneficial, they are expensive. Products of this type are commercially available as Elysol®, containing metronidazole, or as an ointment containing minocycline. Both of these products may be packed in a special syringe and needle, ready for loading into the periodontal pocket.